← Search & browse all drugs

permethrin, combinations

P03AC54

Forms & Strengths

Topical cream: permethrin 1% to 5%
Topical lotion: permethrin 1% to 5%
Aerosol spray/liquid combinations (often with piperonyl butoxide) for lice and scabies

Adult Dosing

Scabies (5% cream): Apply thoroughly from head to soles of feet, leave on for 8-14 hours, then wash off. Single application usually curative.
Pediculosis (1% liquid/cream/lotion): Apply to dry hair, saturate hair and scalp, leave on for 10 minutes, then rinse thoroughly.

Pediatric Dosing

Scabies (infants >= 2 months and children): Apply 5% cream similarly to adults; for infants, apply to scalp, temple, and forehead as well.
Pediculosis (pediatric patients >= 2 months): Apply 1% formulation to dry hair, leave for 10 minutes, rinse thoroughly.

Indications

Treatment of infestation with Sarcoptes scabiei (scabies)
Treatment of head lice (Pediculus humanus capitis) and their nits (in combination products)

Mechanism of Action

Acts on nerve cell membranes to disrupt the sodium channel current by which the polarization of the membrane is regulated
Causes delayed repolarization and paralysis of the pest (parasite/louse/mite), leading to death

Contraindications

Hypersensitivity to permethrin, pyrethrins, chrysanthemum or ragweed allergens, or any component of the formulation
Use on children younger than 2 months of age (unless directed by a physician)

Adverse Reactions

Pruritus (may persist for weeks after successful scabies treatment due to allergic response to dead mites)
Erythema, rash, or localized swelling
Stinging, burning, or tingling at application site
Numbness of the scalp (when used for head lice)

Drug Interactions

Topical corticosteroids: May exacerbate manifestations of scabies by suppressing the immune/inflammatory response (avoid concurrent use if possible)
No significant systemic pharmacokinetic drug interactions due to minimal percutaneous absorption

Curated Content: Needs Vetting Before Put to Clinical Use